Lsp Ping/Trace Over Mpls Networks Using Entropy Labels

1. A method comprising: in response to an initiator node receiving a command to start a connectivity test for a label switched path (LSP), accessing state information stored in memory and determining whether the state information indicates that the LSP comprises an LSP segment that implements entropy label load balancing; in response to determining that the state information indicates that the LSP does not comprise an LSP segment that implements entropy label load balancing, the initiator node generating a first echo request message that comprises a first multipath information type; the initiator node transmitting the first echo request message to a first transit node of the LSP.

2. The method of claim 1 further comprising the initiator node initializing the state information to indicate the LSP does not comprise an LSP segment that implements entropy load balancing.

3. The method of claim 2 further comprising: in response to the initiator node receiving a first echo response from the first transit node, the initiator node updating the state information to indicate that the LSP comprises an LSP segment that implements entropy label load balancing; in response to updating the state information, the initiator node generating a second echo request message that comprises a second multipath information type; the initiator node transmitting the second echo request message to a second transit node of the LSP; wherein the first and second multipath information types are distinct from each other.

4. The method of claim 3 further comprising the initiator node copying multipath information from the first echo response to the second echo request before the initiator node transmits the second echo request.

5. The method of claim 4 further comprising the initiator node copying associated label information from the first echo response to the second echo request before the initiator node transmits the second echo request.

6. The method of claim 5 wherein the first echo reply comprises downstream mapping information and a set of entropy labels.

7. An initiator node comprising: a processor, and; an instruction memory coupled to the processor and configured to store instructions executable by the processor, wherein the processor is configured to implement a method in response to executing the stored instructions, the method comprising: accessing state information stored in memory and determining whether the state information indicates that a label switched path (LSP) comprises an LSP segment that implements entropy label load balancing; in response to determining that the state information indicates that the LSP does not comprise an LSP segment that implements entropy label load balancing, generating a first echo request message that comprises a first multipath information type, and; transmitting the first echo request message to a first transit node of the LSP.

8. The initiator node of claim 7 wherein the method further comprises initializing the state information to indicate the LSP does not comprise an LSP segment that implements entropy load balancing.

9. The initiator node of claim 8 wherein the method further comprises: in response to receiving a first echo response from the first transit node, updating the state information to indicate that the LSP comprises an LSP segment that implements entropy label load balancing; in response to updating the state information, generating a second echo request message that comprises a second multipath information type; transmitting the second echo request message to a second transit node of the LSP; wherein the first and second multipath information types are distinct from each other.

10. The initiator node of claim 9 wherein the method further comprises copying multipath information from the first echo response to the second echo request before the initiator node transmits the second echo request.

11. The initiator node of claim 10 wherein the method further comprises copying associated label information from the first echo response to the second echo request before the initiator node transmits the second echo request.

12. The initiator node of claim 11 wherein the first echo reply comprises downstream mapping information and a set of entropy labels.

13. A non-transitory computer readable medium storing program instructions that, when executed on a processor of a network node, are configured to cause the processor to: access state information stored in memory and determine whether the state information indicates that a label switched path (LSP) comprises an LSP segment that implements entropy label load balancing; in response to determining that the state information indicates that the LSP does not comprise an LSP segment that implements entropy label load balancing, generating a first echo request message that comprises a first multipath information type; transmit the first echo request message to a first transit node of the LSP.

14. The non-transitory computer readable medium of claim 13 , wherein the program instructions are further configured to cause the processor to initialize the state information to indicate the LSP does not comprise an LSP segment that implements entropy load balancing.

15. The non-transitory computer readable medium of claim 14 , wherein the program instructions are further configured to cause the processor to: update the state information to indicate that the LSP comprises an LSP segment that implements entropy label load balancing in response to the network node receiving a first echo response from the first transit node; in response to updating the state information, generate a second echo request message that comprises a second multipath information type; transmit the second echo request message to a second transit node of the LSP; wherein the first and second multipath information types are distinct from each other.